Hydrogen sensor

Abstract

A hydrogen sensor includes a first electrodeand a second electrodeprovided in contact with a proton conduction layer; a gas diffusion controlling portionprovided between a measurement gas atmosphere and the first electrode; and a support element () for supporting the proton conduction layer, the first electrode, the second electrode, and the gas diffusion controlling portion. Hydrogen contained in a measurement gas introduced via the gas diffusion controlling portionis dissociated, decomposed, or reacted by applying a voltage between the first electrodeand the second electrodeto thereby generate protons. Hydrogen concentration is obtained on the basis of a limiting current generated as a result of the generated protons being pumped out via the proton conduction layerfrom the first electrodeside of the proton conduction layer to the second electrodeside of the proton conduction layer. Hydrogen concentration on the first electrodeis controlled to a partial pressure of not less than 10atm, or more preferably, of not less than 3×10atm and of less than 10atm.